[FIX] web_editor: prevent adding data-last-history-step to history

Before this commit, the mutation that add `data-last-history-step` was
added to the history. Without the collaboration, it would not be
problematic but when the collaboration is activated, that step is
broadcasted to the other peers but shouldn't as the mutation is
considered to be technical and should not be included into the
undo/redo mechanism.

task-3217719

Part-of: odoo#114481

Author: Goaman

addons/web_editor/static/src/js/wysiwyg/wysiwyg.js

@@ -205,7 +205,10 @@ const Wysiwyg = Widget.extend({
             },
             filterMutationRecords: (records) => {
                 return records.filter((record) => {
-                    return !(record.target.classList && record.target.classList.contains('o_header_standard'));
+                    return !(
+                        (record.target.classList && record.target.classList.contains('o_header_standard')) ||
+                        (record.type === 'attributes' && record.attributeName === 'data-last-history-steps')
+                    );
                 });
             },
             preHistoryUndo: () => {